The magnifying power of a telescope is m. If the focal length of the eye-piece is halved, then its magnifying power is .........

Options

A. `(1)/(2m)`
B. 4m
C. 2m
D. `m/2`

Answer

B, C

Explanation

Magnification of telescope m =`(f_0)/(f_e)`
If we take `f._e=(f_e)/(2)`
`m.=(f_0)/(f_e)=(2f_0)/(f_e)=2(m)`
`therefore m.=2m`
`therefore`New magnification becomes double.